Faculty Publications
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Item Degradation of Triclosan from Domestic Wastewater by Biosurfactant Produced from Bacillus licheniformis(Humana Press Inc. humana@humanapr.com, 2019) Jayalatha, N.A.; Devatha, C.P.The use of triclosan (TCS), an antimicrobial agent in consumer product, results in adverse effects on the environment due to its wide usage all over the world. The present study focused on TCS detection and attempted for degradation by biosurfactant produced by Bacillus licheniformis from domestic wastewater in Surathkal region, Karnataka, India. The experimental investigation includes biosurfactant production using crude sunflower oil and detection and degradation of TCS from wastewater by High-Performance Liquid Chromatography (HPLC). Results exhibited that maximum biosurfactant yield (7.8 g/L) was achieved using 1 g/L of glycerol as carbon and 5.5 g/L of ammonium bicarbonate as a nitrogen source. Detection of TCS from domestic wastewater (0.36 mg/L) and degradation was carried out by HPLC. The result discloses that 47.2% and 100% removal of TCS was achieved in 2 h and 16 h for 1:1(v/v) ratio of wastewater and biosurfactant. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.Item Novel application of maghemite nanoparticles coated bacteria for the removal of cadmium from aqueous solution(Academic Press, 2020) Devatha, C.P.; S, S.Heavy metals are classified as persistent pollutants owing to their nature of bioaccumulation and affect human life and environment, even in minor concentrations. Divalent Cadmium (Cd2+) is one of the heavy metal pollutants that are highly toxic. The present study investigates the novel application of maghemite nanoparticles coated Bacillus subtilis for the removal of Cd2+ ions from its aqueous solution by batch adsorption studies. Surface characterization of the biosorbent done by Scanning Electron Microscope (SEM) and the presence of maghemite nanoparticle coat was confirmed. Parameters like pH, initial metal ion concentration, contact time, and temperature that affect the biosorption of cadmium ions are analyzed, and the equilibrium adsorption capacity expressed as a function of each of the parameters. The mechanism of biosorption was studied by plotting adsorption isotherms, and it follows pseudo-second-order kinetics. Thermodynamic studies showed the process to be spontaneous and endothermic. At optimum conditions of pH 4, 30 °C, 120 rpm, maximum removal percentage of 83.5%, which accounts for an equilibrium adsorption capacity of 32.6 mg/g of biosorbent. There was a recovery of 76.4% of the biosorbent after adsorption studies. Based on the adsorptive capacity and good recovery of the biosorbent, maghemite coated Bacillus subtilis proves to be an efficient adsorbent for the removal of Cd2+ ions from its aqueous solution. © 2019 Elsevier LtdItem Biomedical Ash as a Soil Stabilizer: Immobilizing Toxic Metals Through Biomineralization(Springer, 2025) Kothuri, M.; Devatha, C.P.Biomedical ash is the residual matter from biomedical waste incinerators. Despite its superior characteristics as a construction material, biomedical ash is usually averted as an additive due to the mobility of toxic heavy metals. Arresting heavy metal mobility has gained the interest of scientific communities due to the ever-increasing waste and continuous demand for construction materials. This research investigated the application of modified ash by calcium carbonate biomineralization as a soil stabilizing agent in highly plastic clays. Initially, the nutrient medium for the indigenous Bacillus cereus bacteria was optimized for maximum urease activity. The ability of biomineralization to arrest mercury, chromium, zinc, lead, iron, copper, cadmium, barium, arsenic, titanium, and selenium in biomedical ash by calcium carbonate biomineralization was determined through a leaching test. The characteristics of modified ash were determined by FESEM, XRD, FTIR, and TG analyses. Adding modified ash correlates with the increasing soil strength, suggesting the suitability of calcium carbonate biomineralization in immobilizing toxic heavy metals and simultaneously enhancing soil strength. © The Institution of Engineers (India) 2025.